Concordance between the Stockholm Workshop Scale and the International Consensus Criteria for grading the severity of neurosensory manifestations in hand-arm vibration syndrome in a Swedish clinical setting

OBJECTIVES: Occupational exposure to vibration using hand-held tools may cause hand-arm vibration syndrome (HAVS). Correct diagnosis and grading of severity are crucial in protecting the individual's health and for workers' compensation claims. The International Consensus Criteria (ICC) has been suggested to replace the widely used Stockholm Workshop Scale (SWS). The aims were to, in a clinical setting, assess the concordance between the SWS and the ICC neurosensory severity grading of vibration injury, and to present the clinical picture according to symptoms, type of affected nerve fibres and the relation between vascular and neurosensory manifestations.METHODS: Data were collected from questionnaires, clinical examination and exposure assessment of 92 patients with HAVS. The severity of neurosensory manifestations was classified according to both scales. The prevalence of symptoms and findings was compared across groups of patients with increasing severity according to the SWS.RESULTS: Classification with the ICC resulted in a shift towards lower grades of severity than with the SWS due to a systematic difference between the scales. Affected sensory units with small nerve fibres were far more prevalent than affected units with large nerve fibres. The most prevalent symptoms were numbness (91%) and cold intolerance (86%).CONCLUSIONS: Using the ICC resulted in lower grades of the severity of HAVS. This should be taken into consideration when giving medical advice and approving workers' compensation. Clinical examinations should be performed to detect affected sensory units with both small and large nerve fibres and more attention should be paid to cold intolerance